Pros

Lessons available offline.
Superbly adapted for the iPhone.
Very well structured content.
Good pace of activity.
Fun exercises.

Cons

Not available in many languages.
May contain some inaccuracies due to crowd-sourced information, especially at higher levels.

Bottom Line

Among free iPhone apps for learning or practicing a language, you can't beat Duolingo, as long as you're studying Danish, Dutch, French, German, Irish, Italian, Portuguese, Spanish, or Swedish.

May 24, 2017Jill Duffy

If you're studying a language, no doubt you've heard of Duolingo, which is the best free program you'll find. The fantastic web app comes with equally free mobile apps that let you practice your language on the go, and the iPhone app is, like the website, the best free language-learning app you can find. The majority of the content mirrors what's on the Duolingo website, and it remains of very high quality. With excellent exercises and a wonderful interface, the Duolingo iPhone app earns a rare five-star rating.

This review focuses on the Duolingo iPhone app and what it has to offer. For a deeper dive into the service at large, see our full Duolingo review.

Supported Languages

If you speak English, the Duolingo iPhone app offers 20 languages for you to learn. They are Danish, Dutch, Esperanto, French, German, Hebrew, Hungarian, Irish, Italian, Japanese (the newest language added), Norwegian, Polish, Portuguese, Russian, Spanish, Swedish, Turkish, Ukrainian, Vietnamese, and Welsh. At the time of this writing, on the full Duolingo website, Hebrew, Hungarian, and Vietnamese were listed as still being in beta. Note that these are the languages available in the the iOS version; you might see a few differences in what's available on Android and the website.

Additional language-learning programs are available for speakers of other languages, so if you have Spanish speaking friends who are looking to practice English, Duolingo has a program for them, too.

Duolingo's list of supported languages has grown quickly over the years, but at least one in-demand language is still missing: Mandarin. Duolingo has a language incubator project, where you can see new languages on the roadmap for rollout. You can also see the full list of available languages and those in beta by going to Duolingo's Courses page.

If you're looking to learn a language now that isn't on Duolingo's list, I would recommend paying for a different program. I've tried many other free mobile language-learning apps, but none are as good as Duolingo. One option to try is Pimsleur Comprehensive, which offers around 50 languages, including many that are harder to find, such as Ojibwe, Twi, and Icelandic. Pimsleur is almost exclusively audio-based, and not as interactive in the technological sense, but it's reasonably affordable and is excellent for learning on the go. You can install Pimsleur's MP3 files on your iPhone in the same way that you'd upload other kinds of music.

If you want more interactive language-learning software and don't mind paying for it, I'd encourage you to move to a full-sized computer or laptop and try Rosetta Stone, an Editors' Choice, or Fluenz, another very good program. Both Rosetta Stone and Fluenz have Mandarin programs. They also both have mobile apps where you can continue your learning. Once you have a subscription, you'll be able to log in to the iPhone app for either one.

What's New in Japanese?

Japanese is a tough language for English speakers to learn, and no two apps approach it the same way. With Duolingo, you learn all the Hiragana characters, all the Katakana characters, and about 100 basic Kanji. I've seen some apps introduce the Hiragana by teaching the proper way to write them, using the touch screen, but Duolingo instead focuses on learning to identify their shapes visually, pronounce them, and hear them.

The characters are introduced thematically, rather than alphabetically, so you aren't learning two or three sounds or shapes that are very similar at the same time.

As with other languages in Duolingo, you can test out of the earliest lessons in Japanese and move ahead to the point in the program that's right for you. But you cannot skip ahead at your own discretion. Content is locked until you pass previous lessons to unlock it.

How Duolingo Works

From a user's perspective, Duolingo works like most other language-learning programs. You work through exercises or activities in order to complete lessons, which are part of larger units. The structure is clear and shown on a dashboard. Icons and short descriptions of the lessons guide you along your language-learning journey. Fully completed sections turn gold, and they stay gold as long as the content is still likely to be fresh in your mind. Sections that you have passed, but are no longer gold, appear in color with a progress bar beneath them. Sections that are currently locked to you because you don't have the skills yet to do them are gray.

The apps sync to keep track of your progress across both your iPhone and in the web app. So you can practice conjugating verbs in German at home and pick up where you left off in the iPhone app during your commute.

A placement test lets new users who are familiar with a language jump ahead to a point in the program that's right for them. Equally helpful is an option to test out of a section, so if you know adverbs really well, you can skip them, so long as you pass the test.

One thing about Duolingo that's different from many other language-learning apps is that you must move through the material sequentially and unlock sections to progress. Other language-learning programs, including Rosetta Stone, Fluenz, and Transparent Language Online, let you bounce around at will.

The core learning is extremely clear to see and work through. The language-learning parts are solid and replicate some of the typical drills you'll find in other language software. Duolingo works your reading, writing, listening, and speaking skills, though you can disable anything that requires your voice input in case you are in a place where talking aloud in a language you don't actually speak might be uncomfortable.

Exercises build on one another, so that you're introduced to words and concepts at the right point in the learning schedule. Typical lessons have multiple choice questions, listen-and-write exercises, and translation exercises. In some exercises, you listen to a sentence and write it in the new language. In others, you translate a written sentence from English to the new language, or vice versa. In the multiple choice questions, I really like that sometimes there can be more than one right answer—you tap checkmark boxes next to whichever correct answers you see.

The service does rely on crowdsourced information to power its language data, and occasionally, especially at the higher levels, you might find incorrect information. However, the errors are few and far between, and much fewer than any other crowdsourced language learning program I've seen.

No matter how you start learning and practicing with Duolingo, you can do so with multiple languages. In other words, for the low, low price of nothing, you can start programs in Dutch, Swedish, and Portuguese if you like, whereas many language-learning programs lock you down to just one language. That's pretty incredible.

Duolingo Bots

In 2016, Duolingo's iPhone app changed its appearance to feature people (or rather, flat images of cartoonish human figures) in some of the exercises. These figures are meant to be speaking to you some of the time, but I find that they take up space unnecessarily.

There's a feature in which you hold in-app chats with these humanoid bots. It's found in an area of the app called Bots. When you start a chat, a little face appears as if you are messaging with the person. She or he typically asks you a question or tells you in the language you're learning to do something, like "Say hi to my friend, Roberto," and you have to take appropriate action. You can't type anything at will. Only certain answers are accepted as correct. And you can't type an infinite number of characters either.

The Bots conversations remind me a little of middle school Spanish oral exams, where you are expected to answer a certain way, repeating back key information ("What does Robert eat?" "Robert eats pizza.") or further the conversation in a specific way ("How are you, Jill?" "I'm well, thank you. And you? How are you?").

You aren't required to use the Bots section, but you will earn points for conversations that go toward your daily and weekly goals. Honestly, I could take them or leave them, so I appreciate that they're optional.

Mobile Design

The exercises in the Duolingo mobile app are very similar to those on the website, but with a few adaptations that make them easier to complete on a tiny mobile phone. In one exercise, for example, the app shows you a sentence, and you must translate it and type it in the language you're learning. On the iPhone, instead of typing each word verbatim, sometimes you see a bank of words from which you choose the correct ones and put them into the correct order.

Duolingo is forgiving of minor typos, which is excellent, especially on an iPhone where the small screen makes it harder to type accurately. The iPhone also makes it easy to insert special characters by pressing and holding any key for options that use that letter as its base.

In the Duolingo iPhone app settings, you can disable sound effects, speaking exercises, and listening exercises, which again is tremendously helpful for a mobile app. You can also dismiss speaking exercises as they come up without visiting the settings. These kinds of design choices are what make Duolingo exceptional.

Practice and Learn With Duolingo

I've been a Duolingo user on and off since the very beginning, and the app has really grown quite a bit, with solid content and language-building exercises effectively packaged in bite-size chunks.

I can easily say that Duolingo is the best free tool for learning a language. The iPhone app works well, handling special characters and some translations with greater ease than even the full web version. It's an ideal way to practice another language anywhere you have a few minutes on your hands. Additionally, it doesn't have to be used exclusively on its own. Duolingo makes for a great companion app to other kinds of language study, whether it's in a classroom or with another piece of software.

Before joining PCMag.com, she was senior editor at the Association for Computing Machinery, a non-profit membership organization for computer scientists and students. She also spent five years as a writer and managing editor of Game Developer magazine, ... See Full Bio